/*
 * Copyright (c) 1998-2012 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *
 *   Free Software Foundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Nam Nguyen
 */

package com.caucho.quercus.lib.db;

public class SqlParseToken
{
  private String _query;
  private String _token;
  private int _start;
  private int _end;
  private char _firstChar;

  public void init()
  {
    _query = null;
    _token = null;
    _start = -1;
    _end = -1;
    _firstChar = '\0';
  }

  public void assign(String query, int start, int end)
  {
    _query = query;
    _token = null;
    _start = start;
    _end = end;
    _firstChar = query.charAt(start);
  }

  public boolean matchesFirstChar(char upper, char lower)
  {
    return (_firstChar == upper) || (_firstChar == lower);
  }

  public char getFirstChar()
  {
    return _firstChar;
  }

  public int getEnd()
  {
    return _end;
  }

  // Case insensitive compare of token string
  public boolean matchesToken(String token)
  {
    if (_token == null)
      _token = _query.substring(_start, _end);

    return _token.equalsIgnoreCase(token);
  }

  public String toString()
  {
    if (_token == null)
      _token = _query.substring(_start, _end);

    return _token;
  }

  /*
   * Return the SQL token as a string. If the token
   * is back quoted, then remove the back quotes and
   * return the string inside.
   */

  public String toUnquotedString()
  {
    String tok = toString();

    // Extract database name if back quoted : "DROP DATABASE `DBNAME`"

    if (tok.length() >= 2
        && tok.charAt(0) == '`'
        && tok.charAt(tok.length() - 1) == '`') {
      tok = tok.substring(1, tok.length() - 1);
    }

    return tok;
  }
}
